Construction material and method of making same



ar 8, 1938. G. A. HOGGATT CONSTRUCTION MATERIAL AND METHOD OF MAKING SAME Original Filed Jam-3, 1953 T. m." Mn 2 a TO N Nu R. m A 7 W.A

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Patented Mar. 8, 1938 G SAME Gilbert A. 110mm, Buffalo, N. Y., assignor m Certain-Teed Products Corporation, New York, N. Y., a corporation of Maryland Application January 3. 193a, Serial No. 049,177 l Renewed June 8. 193'! g g 8 Claims. This invention relates to construction materials, especially'construction materials of fibrous composition. The invention has particular reference to wall boards with edges preformed to particular shapes in order to provide tight joints between adjacent boards. I

The problems .arising in the use of construction materials which must be laid as units or elements of greater or less size includethe proper forma- "10 tion of the joints between such elements to insure continuity of a surface to be exposed or to prevent leakage or infiltration of air thru the structure, as well as to provide a proper support at the joint for superimposed surfacing materials.

Especially in wall boards which are used in abutted relation to form'a continuous surface of the wall is it desirable or necessary that the continuity of the finished surface shall not be marred by the joint and also that the joint shall be strong and of such form as to prevent the leakage of air therethru, particularly when laid upon an outside wall. Moreover, the joint should be of such form in many cases as properly to support a plaster applied upon thewall board and over the joint. It is frequently necessary in such cases to provide a lock for the plaster which will assist in preventing cracking and breaking away of the plaster at the joint.

-To accomplish such purposes in various types of construction materials and in wall board, it has heretofore been proposed to form the edges of the units or elements or of the wall boards with a so-called shiplap or rabbeted edge. Such units or boards may be laid with the rabbet of 5 one unit lapping upon the reverserabbet of an adjacent unit. Moreover, it has heretofore been proposed .so to form such shiplap or rabbeted edges that when the units or the boards are so lapped a space of greater or less width isleft be- 40 tween the adjacent edges of the units or boards on that side thereof which is to be exposed. This arrangement provides a recess into which plaster or other covering material may enter to form a lock for said covering material and makes possible 45 a greater thickness of the plaster over the joint and thereby a stronger plaster joint. v The problem of expansion in such a construction, however, has not been suitably solved;

While such a spaceaswill provide for a lock in 50 some cases will alsotake care ofthe expansion, nevertheless in many cases the abutment of the edge of one of the boards against the rabbet of the other board prevents the free expansion of the board which is necessary to prevent buckling and cracking or breakage of the plaster or covering material if such material is applied to the base surface. Moreover, the methods of producing the shiplap or rabbeted edge in many cases 60 have been wasteful, particularly when making (Cl. Ill- 309).

provision for the space to form a lock for the plaster or covering material.

One object ofthe present invention, therefore, is to provide a form of shiplap or rabbeted edge for covering units or for wall boards which will incorporate the features of the forms of units and wall boards heretofore proposed but which will properly take care ofthe expansion. Another object of the invention is to provide a a method of making such rabbeted edge units or wall boards which will avoid waste of material and secure a production thereof at low cost.

In order to provide more effectively for the expansion which occurs in construction units and which results in buckling of the units orv cracking of the surface thereof or cracking and breaking away of materials such as wall plasters applied thereto, the present invention proposes a form of rabbeted joint in which provision is made for expansion of the joint by means of a space between portions of the adjacent edges of adjacent units while other portions of the-edges are in substantial abutment. The edges, however, are so formed that the portions in abutment may yield under the force of expansion without undue deformation or distortion of these portions to affect adversely the covering material applied thereto. Provision is made, therefore, both for the lock of the covering material such as plaster and for the expansion of the base unit such as a wall board. Cracking and breaking'of the plaster or covering material at the joint are thereby prevented and buckling of the units, and consequent cracking of the face of the covering material or plaster which occurs when the base is not free to expand is also prevented.

The method of the invention comprises the severing of the material from which the unit is to be formed in such a way as to remove a minimum of material, as by a fine saw cut, and the subsequent separation of the two portions of the material along a line connecting the cuts.

In the formation of a rabbeted edge two such 1 saw cuts may be'm ade transversely of the surface of the unit on opposite surfaces of said unit, said cuts being spaced from each other in a direction parallel to the surfaces. The cuts do not extent thru the unit from one surface to the other and the line of severage or cleavage substantially the usual method of producing connects the inner ends of the two cuts in the 'Figure 6 shows a modified form of the units of the invention; and

Figure 7 shows an assembly of the as in Figure 6.

In Figure l is shownain cross-section oneJem -y bodiment of the joint of my inventioniillustratingl the application of the invention to a' Joint-between wall boards. Thewall board lis'formed at its left hand edge in Figure 1 with-a 'rabbeted' recess provided by the surfaces 2 and I. The tongue 4, of which the surface 2 forms the-surface to be lapped upon the rabbeted edge of an I adjacent-board, is formed with a bevel surface I extending from the V-shaped, edge}. reversely upon the. tongue 4. v'Ihethi'cknessofthe tongue i appr im eei i 'r ss 1 t board I, and correspondinglythe 'depthi of the surface 3 is approximatelyone half thethick ness of said board;

tongue l0 havingan endsu'rfacell I and a longiis approximatelyone-halfthe'thickness of the board. Thus the surfacelllisi about 'at themidner end of the surface 12 of thelton'gue Ill a bevel surface ll extends, inwardly toward the center of the length of "the board but outwardly toward the upper surface 1 thereof to form with the surface I! an obtuse'anglel .Thelangleof the bevel surface. II withfrespect. to i l' ev upper surface I of the board may be substanflflllyl the same'asthat of the surface lnwithsaidupper surface "I. However, if desired, the angles of these two surfacesmay be different to suit'particular conditions.

, It willbe noted from Figure'll showing such wall boards, one lappedupontheothenthat the v-shaped edge} substantially abuts against the bevel surfacejll of the adjacent boardi g}; v theflsurfaces 2 and I! are substantially longitudlnally of the width of. thefboard,these.sinfaces "I; terial removed by the saw cutsnecessary to cut in adjacent units ma move with-respect ml ea h other as in any shiplap construction. [While these surfaces 2 and, [2 have been showncas straight lines, they 'may be otherwise formed to one with respect to the, other is such that the overlapping tongue I of one. boardmaymove upon the overlapped tongue "of theadiace'nt board without substantial] distortion. of the tongues or substantial movement transverselv of the surfaces of the boards. As the ycedge of the surface it of an adjacent board under'the force of expansion, a slight yielding or compression or even a slight crushing of such V eqren y mun As the edge I presents only a smaliamount of material against-the surface lt such yielding "or even such crushing will 'not'produce substantial deformation of the Joint and'plaster or other covering material applied upon the surface" 1 producing edges of the boards have been so formed that ,when the V edge 6 abuts the surface II the edge 1 II" will abut the surface 3 of the rabbet of the adjacent board. It has been found to be difllcult to persuade workmen to leave space for expansion. as it is easier to abut the boards when layiing. Thus no provision has been made for expansion of the board because the abutment of L the'surfaces Hand 3 prevent relative movement of said boards. In the present invention, as shown in Figurel, a space is left between the end, ,edge. surface ll of the tongue I of one board and the surface a of the rabbet of the overlapped board. When expansion of the boards takes place the edge if may move toward the surface l witluput v bringing pressure thereon -which will cause the boards to buckle or which will bringupon the Joint forces which will tend to seni r ,thedoint and cause, cracking of the plaster applled'thereto. It now should be clear that to p'rovide'the space between the surface Ii and thesurfacelitis necessary to form the surv v e face l2 of theoverlappedtongue l0 on'oneedge At the opposite edgeof the board vI .and in the reverse hand fromfthe tongue {I is formed the of the board withlesslength in the direction of 7 direction or the surface 2. As may be seen in tudinal surface I2. The heightofthelsmifacell Figure '1, the difference in length of the surface 2 andof the, surface I! in the overlapped arv H V ,rangement. of the boards leaves the necessary die of the thickness of the board. From theinspace between-the'surface ll andthe surface 3 a particular example of the proportions 'Qfwhi'ch are practicable for the embodiment of the invention, those suitable for a wall board may jubeigiven. ,For so-called insulating lath which {is a base forplaster or; stucco, sheets or panelsfofthe standard size of ,96 inches length by'dilinches width maybe reduced to smaller fpanels or approximately 48 inches by 16 inches Ito form the insulating lath. The width of shiplap boards, shown in the figure by the dimension A, in this particular example correspondingly ,would be approximatelylo inches from the V vedge]! tofl the corner formed by surfaces l2 and it} }In the,,ordinary laths the amount of ma- ..th'e' panelinto the smaller. laths would have to beallowed, for. As an example of the dimensions for the rabbetededges, the following I may be given: For a thickness of board about suit different conditions providedythe form 'of 3 the-length of the. surface, rmy be about $6" andmsi'mila'rly the dimensionof the surface If a is approximately /4,". Thus the surfaces 2 and overlapping tongue 4 moves againstthe bevel Q the thickness of the board. ,The angle of the i2 jarepositioned substantially at the center of bevel surfaces 5 and I3 may beconveniently 45 degrees or ln someca'ses the angle which these surfaces make with the surface 'lfupon which plasteris'to be applied may be approximately "'120"de'grees." Various modifications -of the dimensions maybe made within the scope of the "invention; and ino'rder toinsure alignment of the surface's 1 slight clearances between the surfaces'l'and' 12: may be provided for. Moreover, in different forms of units different dimensions jacent board but that ample space is allowed between the surfaces. II and} for such expansion without bringing the surfaces II and 3 into contact. a

Figures 2 and 3 illustrate the present method of forming shlplap edges and the method of dividing a material, such as a wall board, into smaller portions having, such edges. In some cases the cut l6 may be made in the face I! of the board and a similar cut it may be made in the opposite face 19. If these cuts are suitably positioned with respect to each other and if the depth and width of the out are suflicient, the two portions of the board may be cut apart in forming the cuts i8 and I 8. In some cases it may be necessary to make an additional cut through the board in order to separate the two portions there-v .of if the cuts l6 and ,II do not meet and cut through the material. Usually, however, inthe present practice the sections are first cut from the panel and the rabbets then are formed on each piece. In any case, it will be clear that the amount of material which is wasted is that represented by the full width of the cut l6 or of the cut i8 and that as well care must be taken to cut through the board or additional operations become necessary. When the separated pieces are lapped upon each other as in Figure 3, it will be clear that the amount of area covered by the boards is as much less than the area of the original material as the sum of the cuts at one' face of the board.

In Figure 4 is illustrated the method according to the invention of dividing material into smaller portions so as to avoid the'wast'e of the material usually necessary to form the rabbeted edge. A simple, quick and convenient method of forming such rabbeted edges is provided. The

' method is illustrated in this figure in connection with wall board having a-body structure such as will permit cleavage longitudinally, that is, in a line extending inrthe same direction as the face of the boards, Such a body structure is provided in many types of construction materials including 'wall boards which have a laminated structure or those which are constructed in a. felting or matting operation to produce a more or less homogeneous or'fmonollthic" body structure, which structure has a grain or an arrangement of the fibres longitudinally of the board. Such body structures, whether in fibrous materialsor in other materials, make possible the cleavage of the body structure longitudinally of the board. The invention comprises wall boards and other construction 1 units and materials which have a body structure which makes possible the separation of the material of the unit or board along such so-called longitudinal. lines. For example, in a wall board of laminated construction, whether of flbrious or other material,

. thefmethod, of the invention finds application to produce the forms of rabbeted edge which here- I tofore have been used in the art or those proposed by the present invention as described above. In Figure 4 illustrating the method of forming such rabbeted or shiplap edges in a wall board a narrow saw cut 20 is made part way thru the board. from one face 2i thereof. This cut is shown as being made at right angles to the face II of theboard. but the cut may be made at any suitable angle, depending upon the result desired. At 22 is shown asecond saw cut made part way thru the board from the opposite face 28 thereof. It will be noted that these cuts are not in line and do not meet at the center of from each other. In the formation of a simple shiplap or rabbeted edge, such as is usedin wall boards, this cleavage may readily be accomplished by a tlexure of the panel from which the two pieces ofboard are to be formed so that the force is applied to the line of cleavage and the separation takes place along this line. In Figure 51s a simple illustration of the step of flexure to secure separation of the two portions of the board. The small pieces at the edge of the panel from which the boards or laths are made similarlylmay be removed by cleavage.

It will be apparent that the saw cuts 20 and 22 may be made simultaneously with suitable apparatus by running the panel or sheet of wall board orotherconstruction material both under one saw, to produce the upper cut 20, and over a saw placed beneath the cutting table, to produce the lower cut, 22. Moreover, in cutting a panel into a number of units a plurality of such sets of saws may be used so that in a single pass of the material thru the apparatus all the necessary saw cuts are made. Subsequently by a simple action of bending or flexureof the portions on each side of the pair of cuts the cleavage In order to form the V-shaped recessesorv beveled surfaces which have been described above in connection with Figure l, a cutter or insome cases a grinding wheel which has a form in section to. provide at its rim a V of the desired angle and of the desired position with respect to the. plane of rotation, i. e., whether symmetricalwith said plane of rotation of said cutter or otherwise, may be used. Thus also in one operation a bevel edge board may be produced in themanner described in connection with Figure 4. Moreover: as

may be seen from Figures 1, 6 and 7 by using'a,

saw or cutter of proper width for the lower cut '22 the width of the space between the surfaces H and 3 as shown in Figure 1 may be made such as to leave room for expansion-of the boards. By suitably positioning the saws or the cutters or the grinding wheels, the dimensions desired for the surfaces 2 and 12 as well as for the relation of the other surfaces of the edges of the board may be obtained. All such adjustments may be practiced with variations of both the kinds of devices used and the particular action thereof within the scope of my invention.

In applying the invention in the production of units or elements of some kinds ofmaterial the cleavage or breakage of the body structure of the material along the line of cleavage may or from the interspersed relation of the particles forming the body structure, said particles having parts thereof extending over the line of cleavage into the body structure on the opposite side thereof. In some cases such rough surfaces are. not a disadvantage, particularly when, the units or elements are to be lapped again in the same position as that in which they were broken apart, as shown in Figures 1, 4 and 5. In some cases, however, it is desirable to form one of the saw cuts 'with a wide width and the other with as little width as is practicable. The difference between the widths of the saw cuts will provide for a recess between adjacent boards at one surface thereof when the other portions of the rabbets are abutted, as shown in Figure 7. In such a case 'it may be necessary when a rough surface results from the breakage or cleavage to smooth these surfaces by running the separated units or portions over an emery wheel or other device to bring the rough surface down substantially to the center of the width of the board.

This is the more necessary when units such as wall boards are to be arranged upon a supporting structure without any superimposed coating such as plaster which will co"er the joint although ,in some cases it may be necessary to smooth the rough surface in order to insure that the exterior surfaces of two adjacent boards shall be aligned.- Such may be the case when a paneling strip, such as a wood strip, is placed over the joint. Wall boards or insulating laths having rabbeted or shiplap edges may be produced for such use by the simple operation of cutting the slots and breaking the sections apart as has been described above.

While the -invention has been described and illustrated more particularly in connection with wall boards, it is applicable to other types of construction units and construction materials. In all such materials, whether of granular or fibrous or other body structure, which have or may be formed soas tohave a line of cleavage extendthe edge of each piece.

ing generally in the same direction as the faces to be exposed, the method of the invention may b'eutilized by forming recesses, whether by cuts into the body of the material or recesses molded or otherwise'made in the face of the material before separation. Such recesses or cuts reach into a cleavage line along which the adjacent portions may be separated'to form the rabbet on In particular, however, he invention is useful to the formation of shiplap edges or panels of wall boards of fibrous materials which have not a great resistance to cleavage along the layers or along the grain of the fibre extending generally in the direction of the faces of said panels or boards.

What is claimed is:

1. The method of forming rabbeted edges in a structural unit which comprises cutting part way thru the material from which the unit is being made to a line of cleavage therein, cutting thru said material from another side thereof to meet said line of cleavage at a point thereon different from that at which the first cut meets said cleavage line, and so applying force to said material as to cause cleavage thereof along said cleavage line joining said cuts.

2. The method of forming rabbetededges in a structural unit which comprises cutting part way thru the material from which the unit is being made to a line of cleavage therein, cutting thru said material from another side thereof to meet at points separated longitudinally thereof from opposite faces thereof and transversely to said faces at least to a depth such that each cut meets substantially the same line of cleavage, and separating said portions on either side of the cuts by cleavage along said cleavage line.

4. The method of forming shiplap edges upon fibre wall board having the grain of the fibre for the most part extending in the same general direction as the face of the board, which comprises forming a out part way thru the board transversely to one face thereof, forming a second out part way thru the board transversely to the opposite face thereof, said cuts being laterally spaced and extending substantially to a grain of the fibre connecting said cuts, and separating the portion of the board at one side of the cutsrabbet, which comprises forming a relatively narrow cut of a length to extend only part way thru the material from which the unit is being made from one side thereof, forming a relatively wider cut laterally removed from said first cut and extending part way thru said material from another side thereof, and causing the material to separate substantially upon a line joining said cuts.

6. The method of forming upon a structural unit rabbeted edges of unequal length of the rabbet which comprises forming a cut extending part way thru the material from which the unit is being made from one side thereof, and forming a second cut laterally removed with respect to,the line of said first cut and extending part way thru said material from another side thereof, and causing the material'to separate substantially upon a line joining said cuts, the width of said second cut and the position thereof with respect to the line of said first cut determining the relation of the length of the rabbets.

'7. The method of forming upon a structural unit rabbeted edges of unequal length of the rabbet, which comprises forming a relatively narrow cut of a length to extend part way thru the material from which the unit is being made from one side thereof, forming a relatively wider cut to extend part way thru said material from the opposite side thereof, said cuts being laterally offset from each other and being of such depth that if in alignment the bottoms of said cuts would substantially meet, and severing said material along a line joining the bottoms of said cuts.

8. A pair of structural members each having upon a face thereof a rabbet formed at an edge of the member, said members being formed of the same piece of material and having planes of cleavage generally like-extending with said faces, the lapping surfaces of said. rabbets of said members being the complementary cleavage surfaces along a common plane of cleavage of said material.

GILBERT A. HOGGA'I'I. 

